Put that sac in the middle of the boat and go. The trim tab will not really help produce a good SOLID wake at speed. I/O's are tricky.

I have found some want a lot of weight in the stern, but you can never go wrong with weight in the middle. It will make the wake a lot more solid and hopefully let you ride a little further back. My only hang up with riding behind an I/O is that you ride between 55' and 65'.

Definitely play with the trim. On some I/O's and outboards you can get a very nicely shaped wake if you trim the oudrive up a little bit. It varies from boat to boat, so play around with the trim and try putting the fat sac in different places (your best bet will probably be somewhere in the middle or front of the boat).

The trim all the way down pushes the boat nose down, similar to having more weight in the front. If you are push your trim all the way down and have trim tabs you can push down, it will force the nose down even more. The best thing anyone can tell you to do with your boat is to try everything. Just go out one day and move things around until you get the wake the best you can. Just remember, when you add gear or people or more/less fuel, it will change the wake shape and size. It is all trial and error.

you can get a lot out of an i/o if you do it right. On our old 95 sea ray we ran with the trim at about 3/4 up (started with it down, then ran it up once on plane) the higher the trim the better with that boat, but too high and the boat will bounce. Then you just have to get your weight just right. Takes work and every i/o is different. Still, lie they said, make note of your people and keep your gas tank full.

.....ultimately on an i/o wakesize too is related to weight in the boat. Once you really weigh down your boat with 1200+ lbs....you will need a lower pitch prop and trim always all the way down (otherwise you will have difficulty planing or holding speed or washy wake etc...).....there comes a point with weight were moving the trim up any amount will not be beneficial. the only time it will help somewhat is if you are not carrying a lot of weight....but then you really aren't close to using the potential of the boat. And once you do load your boat...no matter what you need weight in the front. You will find that wakes really gain in size and meatyness with good weight in the front...and for an i/o really helps the boat to plane out. Its not for fun that we have bow sacs out there going up to 1100lbs. Then peeps in the front too. If you have 600 in the back try 400 up front and trim down see where that takes you....if you have problems holding speed or planing put peeeps up there...if still problems.....get a prop with a lower pitch. Remember when trying to get a nice wake you are trying to sink the whole boat not just the rear end.....while that can produce an okay wake it wont match a fully sunk boats wake in size or volume.

I have found that trimming up helps my wake a ton. I'm working with a 99 sea ray 190 (about 20' boat). Every setup is different but I'm working with a 5.0 v8 EFI 240 hp. I've put a 17 pitch 5 blade prop & run about 1200 of ballast + 3-5 people. I also have bolted the stingray hydrofoil - the poor mans wedge. I place 400 in the bow, 350 in the ski locker, 350 in front of the rear bench seat & another 1-200 moved around as needed. When I get up to speed, I trim the outdrive up almost as far as I can without porpoising. The hydrofoil pulls the rear end of the boat deeper into the water, which helps the wake, as long as there is weight in the front to balance it. This puts out a pretty stout wake up to maybe 23 mph & 75 ft out. Any faster & the boat sits up too high & the wake flattens.